Specflow
FreeNot checkedAgentic harness for large-scale AI code generation - by Grid Dynamics
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Agentic harness for large-scale AI code generation - by Grid Dynamics
README

Agentic Harness for Large-Scale Code Generation
AI agent harness for automated code generation and complexity estimation. Multiple deployable codebases built by multiple SOTA AI models. When their code complexity scores align, it proves the specs are complete.
SpecFlow is an AI agent harness that automates code generation, deployment, and testing through parallel AI agents in isolated, sandboxed execution environments.
Validator agents continuously assess, resume, and refine work until delivery standards are met.
https://github.com/user-attachments/assets/0783c394-1bf0-449f-a36e-1d46e899661c
Getting Started
Software
| Requirement | Notes |
|---|---|
| Docker | Container runtime for the harness sandbox. Install Docker |
uv |
Python package manager. Install via brew install uv or see docs |
| IDE | SpecFlow is used as MCP in a IDE with agentic AI enabled: Cursor, Claude Code, Copilot, Gemini etc. This is the users project. |
Keys and Tokens
| Key | Name in .env |
Notes |
|---|---|---|
| GitHub Personal Access Token | GITHUB_TOKEN |
For disposable workspace repos. Scope: repo + read:user + workflow repo,read:user. Advan |
| P10Y API key | P10Y_API_KEY |
Code complexity scoring. Setup guide |
| LLM provider key | OPENROUTER_API_KEY or ANTHROPIC_API_KEY |
One key required. Get OpenRouter key (default) or Get Anthropic key |
Installation
Few simple steps to get you going:
- clone repo
git clone https://github.com/griddynamics/specflow.git && cd specflow - install Specflow (includes the Terminal UI that guides you through onboarding)
uv tool install --editable ./mcp_server - start Specflow app and follow instructions
specflow tui
[!Important] Specflow Harness Sandbox is now running locally. Easiest: in
specflow tui, pressc(Add MCP to AI tool) — the setup screen detects Claude Code, Gemini CLI, and Cursor and wires SpecFlow up for you (one key), with an honest connected/added/failed status per client. Prefer to do it by hand? Copy-paste the content of.specflow-local/mcp-config.jsoninto your client.
Cursor |
Claude Code |
Claude Desktop |
Copilot |
Gemini CLI |
...and any other IDE or client that supports the Model Context Protocol.
Usage
MCP is now ready to use in any project. Prompt your IDE agent to talk to the harness.
Let's say specification files are in specs directory, you can follow these steps:
Start a new project in IDE and put your specs files into
specsdirectoryspecs/ |-- product-requirements.md |-- user-flows.pdf \-- acceptance-criteria.mdCheck your specification completeness using
check_specification_completenesstoolUse SpecFlow MCP to check specification completeness in specs directoryCreate a detailed plan using our
run_planningtoolCreate implementation plan using SpecFlow MCPWhen you are happy with the plan, run generation using
run_generationas aboveRun generation with SpecFlow MCPGeneration usually takes many hours, use our TUI to monitor progress and receive Desktop Notifications:
# Any terminal specflow tui

When the generation has been completed, you can retrieve the results and P10Y reports from harness:
Download outputs using Specflow MCPThe rule of thumb is: if the P10Y score spread is low, then your specification is ready!
Use the built-in prompt to compare the variants and identify their strong and weak sides, together with a plan to automatically assemble the best variant.
use SpecFlow MCP prompt: specflow-compare-variants
MCP Tools
| Tool | Description |
|---|---|
check_specification_completeness |
Analyze specs for gaps and contradictions (local) |
run_planning |
Generate a phased implementation plan (local) |
read_document |
Extract PDF/DOCX/PPTX/XLSX/CSV to markdown (local) |
run_generation |
Upload and launch parallel codegen on the backend (2-8 hrs) |
check_status |
Poll generation progress |
download_outputs |
Download archived artifacts from a completed run |
retry_generation |
Retry a failed generation |
If you want to go deeper
Install only SpecFlow skills
We have portable set of skills that is normally used as preparation phase for Human-In-The-Loop AI assisted specification checks and planning.
Example for Claude Code:
/plugin marketplace add griddynamics/specflow
/plugin install specflow
SpecFlow Detailed Overview
https://github.com/user-attachments/assets/ea1dd95d-5742-4c51-bf2c-c2cb582669c3
Full MCP config and usage: MCP_USER.md
Full MCP API reference: docs/mcp/API_REFERENCE.md
Detailed SpecFlow harness instructions: QUICKSTART.md
[!Important] AI agents work in scratchpad repos that are reset before each run — we create them for you. **Do not point SpecFlow at repositories with code or history you want to keep. ** The managed SpecFlow service is for Grid Dynamics employees only. Open-source users should run the local quickstart.
Documentation
| Document | Description |
|---|---|
| QUICKSTART.md | Local setup and first run |
| CONTRIBUTING.md | How to contribute — workflow and PR checklist |
| CLAUDE.md | Development protocol and STEEL commandments |
| TOKEN_ECONOMY_GUIDANCE.md | Token economics and model choice — budgeting AI spend predictably |
| docs/ARCHITECTURE.md | System design and data flow |
| docs/mcp/API_REFERENCE.md | MCP tool reference |
| docs/backend/DEVELOPMENT.md | Backend development guide |
| docs/backend/API_REFERENCE.md | REST API reference |
| docs/operations/TROUBLESHOOTING.md | Troubleshooting guide |
| docs/IDE-SETUP.md | IDE configuration (Cursor + Claude Code) |
| docs/examples/deployment-spec-example.md | Example spec for agentic deployment + E2E tests |
| SECURITY.md | Security policy and vulnerability reporting |
Contact
Questions, feedback, or anything that doesn't fit a GitHub issue: [email protected]
Found a security vulnerability? Please report it privately per SECURITY.md rather than opening a public issue.
License
MIT — Copyright (c) 2024 Grid Dynamics International, Inc.
Installing Specflow
This server has no published package — it is built from source. Open the repository and follow its README.
▸ github.com/griddynamics/specflowFAQ
Is Specflow MCP free?
Yes, Specflow MCP is free — one-click install via Unyly at no cost.
Does Specflow need an API key?
No, Specflow runs without API keys or environment variables.
Is Specflow hosted or self-hosted?
Self-hosted: the server runs locally on your machine via the install command above.
How do I install Specflow in Claude Desktop, Claude Code or Cursor?
Open Specflow on unyly.org, pick your client tab (Claude Desktop, Claude Code, Cursor) and press Install — the config is generated automatically, no JSON editing.
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